What is a triplex DNA structure?
A DNA triplex is formed when pyrimidine or purine bases occupy the major groove of the DNA double Helix forming Hoogsteen pairs with purines of the Watson-Crick basepairs. Intermolecular triplexes are formed between triplex forming oligonucleotides (TFO) and target sequences on duplex DNA.
Who discovered H DNA?
The molecule now known as DNA was first identified in the 1860s by a Swiss chemist called Johann Friedrich Miescher. Johann set out to research the key components of white blood cells?, part of our body’s immune system. The main source of these cells? was pus-coated bandages collected from a nearby medical clinic.
How do triplex drugs work?
The purine anti-parallel triplex motif utilizes TFOs made of A and G. They bind to the major groove of DNA in an anti-parallel sequence-specific manner by forming reverse Hoogsteen hydrogen bonds with the purine-rich target strand (3,60).
What is a DNA and B DNA?
A-DNA is thought to be one of three biologically active double helical structures along with B-DNA and Z-DNA. It is a right-handed double helix fairly similar to the more common B-DNA form, but with a shorter, more compact helical structure whose base pairs are not perpendicular to the helix-axis as in B-DNA.
Do any animals have A triple helix?
Triple Helix Animals are unique animals that have the ability to cause strange environmental effects to their habitat. There are a total of 7 Triple Helix Animals, that the team needed to collect in order to find a cure for the animals, and Jackson Oz.
What are types of DNA?
There are two types of DNA in the cell – autosomal DNA and mitochondrial DNA. Autosomal DNA (also called nuclear DNA) is packaged into 22 paired chromosomes. In each pair of autosomes, one was inherited from the mother and one was inherited from the father.
What are triplex drugs?
Triplex is a tricyclic antidepressant, prescribed for depression. It is also prescribed for migraine and nerve pain. It corrects the imbalance of chemical substances acting on the nervous system.
What are triplex forming oligonucleotides?
Definition. Triplex-forming oligonucleotides bind in the major groove of duplex DNA in a sequence-specific manner through the formation of hydrogen bonds. They can be used to inhibit the expression of particular genes.
How does a duplex DNA form a triplex?
66 FRANK-KAMENETSKII & MIRKIN P-loops while interacting with duplex DNA forming triplex with one of DNA strands leaving the other strand displaced. Very unusual recombination or parallel triplexes, or R-DNA, have been assumed to form under RecA protein in the course of homologous recombination.
How are intramolecular triplexes formed in vitro?
Intramolecular triplexes (H-DNA) are formed in vitro under superhelical stress in homopurine-homopyrimidine mirror repeats. The average negative supercoiling in the cell is not sufficient to induce H-DNA formation in most cases.
Which is a feature of the yr * y triplex?
An important feature of the YR*Y triplexes is that formation of the CG*C triad requires the protonation of the N3 of cytosine in the third strand. Thus, such triplexes are favorable under acidic conditions (3, 4). By contrast, the YR*R triplexes usually do not require protonation (see below).
Where is the third strand of the double helix?
To form such triads, the third strand must be located in the major groove of the double helix that is forming Hoogsteen hydrogen bonds (24) with the purine strand of the duplex. The remarkable isomorphism of both canonical triads makes it possible to form a regular triple helix.